1. Field of the Invention
The invention relates to a method and to a control unit for operating a volatile memory.
2. Description of the Related Art
A digital trip recorder, which is also called a digital tachograph, stores events that are related to vehicle operation for a predetermined period of time on a driver-oriented chip card. Thus, for example, steering, working, standby, rest, and interruption times are stored. The collective data can be read out digitally by inspection authorities or a keeper of the vehicle in accordance with predetermined legal regulations. The storage of the data is subject to high requirements.
JP 2001142508 A discloses a circuit arrangement comprising a RAM memory which can be separated from its supply by a switching element.
US 2006/0133135 A1 discloses an array of SRAM cells driven by control electronics. In this arrangement, a voltage for supplying the SRAM cells is higher than a voltage for supplying the control electronics.